Method for extracting hydrocarbon compounds, especially crude oil, from underground oil sands deposits

ABSTRACT

A method for extracting hydrocarbon compounds, especially crude oil, from underground oil sands deposits, including the following steps: at least two parallel boring sections are created in the oil sands deposits; at least some areas of the boring sections are filled with an explosive material; the explosive material is ignited in order to enlarge the boring sections; the combustible material is ignited in at least one of the boring sections in order to convert the hydrocarbon compounds in the oil sands deposit into a liquid and/or gaseous state; the hydrocarbon compounds in a liquid and/or gaseous state are collected; and auxiliary substances such as water and atmospheric oxygen are optionally introduced and removed for desired material conversions for the refining of hydrocarbons.

The invention relates to a method for extracting hydrocarbon compounds,especially crude oil, from underground oil sand deposits.

Processes known as ISC (in situ-combustion) processes are known for thesubterranean separation of low-fluidity bitumen from oil sand. In thisprocess, the bitumen present in the oil sand is partly combusted and,for this purpose, air is injected into the porous oil sand, via a boreintroduced into the oil sand deposit, in order to enable suchcombustion. The high-viscosity bitumen made fluid by the combustion isthen pumped off via drainage pipes. In such processes, a firefront isproduced within the oil sand deposit, and moves through the deposit.Controlling the firefront presents problems.

Alternative processes are based on the introduction of hot steam intothe oil deposit, in order to make the high-viscosity bitumen fluid andallow it to be pumped off.

The aim of the invention is to improve a method for extractinghydrocarbon compounds, especially crude oil, from underground oil sanddeposits.

According to the invention, a method is provided, for this purpose, forextracting hydrocarbon compounds, especially crude oil, from undergroundoil sand deposits, with the steps of introducing at least two boresections parallel to one another into the oil sand deposit, of at leastsectionally filling the bore sections with an explosive material, ofdetonating the explosive material to enlarge the bore sections, ofigniting combustible material in at least one of the bore sections, toconvert the hydrocarbon compounds present in the oil sand deposit into aliquid and/or gaseous state, and of collecting the hydrocarbon compoundspresent in a liquid and/or gaseous state.

The method of the invention permits improved in situ bitumen extractionand also improved upgrading of the hydrocarbon compounds with a higherand more rapid yield than in the case of the prior art described. Bycreating an underground cave system or cavern system through theintroduction and enlargement of bore sections, the hydrocarbon compoundscan be collected more easily and completely. Moreover, it is possible,for example, to blow in air, steam, or the like with substantiallygreater control and simplicity, since enlarged bore sections areavailable. In accordance with the invention, bores are sunk in the oilsand by means of a suitable drilling apparatus. After the bores havebeen introduced into the oil sand, bore sections lying within the oilsand are filled, at least sectionally, with an explosive material, andthis explosive material is detonated. As a result, a stable,approximately cylindrical cavern is formed in the oil sand. At least twosuch caverns are produced parallel to one another. Then, in at least oneof the caverns, combustible material or ignitable mixture is provided,for example, by the pumped introduction of additional air, and thismaterial or mixture is then ignited by means, for example, ofpyrotechnic detonating charges. The combustion is then maintained. Hotcombustion gases then penetrate the porous oil sand and liquefy thebitumen in the sand. The combustion then progresses also preferably inthe radial direction into the surrounding oil sand. In the cavernitself, liquid and/or gaseous bitumen and/or other hydrocarbon compoundsthen collect, and can then simply be pumped off. Through targeted, blownintroduction of air and water/steam or other substances, temperatureconversions and physical conversions within the caverns can beinfluenced. When the bitumen source is exhausted, i.e., the combustionzones and/or the liquefaction zones, which advance in the radialdirection from the two caverns, come together, the supply of air is shutoff. Optionally, CO₂ may be pumped in to halt the combustion reliably.The bore sections can be enlarged underground without problems, bydetonation of the explosive material, and this enlargement representsthe precondition for a decisive improvement in the method of theinvention, as has already been the case in particular with regard to themore rapid, more complete, and more secure collecting of liquid orgaseous hydrocarbon compounds, and also in respect of the morecontrolled propagation of a flame front in the oil sand.

In development of the invention, there is compacting of the oil sandmaterial surrounding the outer surface of the bore sections, by means ofthe enlarging of the bore sections after detonating of the explosivematerial.

Compacting the oil sand material produces stable caverns which can beutilized for the passage of gaseous and liquid hydrocarbon compounds andalso of additives, and also for the combustion of combustible material.Especially in the case of porous and plastically deformable oil sand,such compaction may take place very easily by detonation of explosivematerial in a bore section.

In development of the invention, air is supplied to the bore sections topromote the combustion of the combustible material, and off-gases formedduring combustion are drawn off under suction.

In this way it is possible to maintain controlled combustion withpredetermined parameters in the enlarged bore sections. Since theenlarged bore sections form caverns, such control or regulation ofcombustion can take place reliably, since physical exchange is possiblecomparatively rapidly in the volume of the caverns, in any casesignificantly more rapidly than would be the case for the blownintroduction of air or gases in porous oil sand.

In development of the invention, water, steam, oxygen, carbon monoxideand/or carbon dioxide is supplied to or targetedly withdrawn from thebore sections in order to influence temperature and physical conversionsin the region of the bore sections; in this case, carbon monoxide and/orcarbon dioxide may also come from the combustion itself.

In this way it is possible to design an underground refinery withcontrollable combustion parameters, physical conversion (upgrading)parameters, mass transport parameters, and heat transport parameters inthe caverns formed by enlargement of the bore sections. For example,with the aid of gravity and of the flow regime of gases, moreparticularly air, combustion gases, pyrolysis vapors or smolder vapors,hydrocarbon vapors, etc., and liquids (hot bitumen and crude oil) can bespecifically influenced. Temperature zones can be influenced in just thesame advantageous way. In addition, as in the case of above-groundupgrading processes, specific physical conversions can be achieved andtherefore partially cracked bitumen also upgraded by hydrogenhydrotreating (synthetic crude oil) can be synthesized underground. Thisis accomplished, for example, by occasional (intermittent) or continuousinjection of water or steam into a cavern filled with combustion gasesand bitumen vapors. In a manner similar to steamcracking or thermalcracking, long-chain hydrocarbon molecules are split, and subsequently,using synthesis gas (CO and H₂ from steam and pyrolysis coke),unsaturated, short-chain hydrocarbon molecules are saturated withresultant hydrogen, also called hydrotreating. In order to controlcombustion or to extinguish the combustion zone, after the end ofexploitation of the deposit, using CO₂ introduced by pumping, carbondioxide, for example, can be pumped in. In this way it is also possibleto a certain extent to store CO₂.

In development of the invention, the hydrocarbon compounds present inthe oil sand deposit are split by means of the combustion intohydrocarbon chains of different lengths and different aggregate states,with short-chain, lighter and/or gaseous chain components rising upward,and long-chain, heavier and/or liquid chain components falling downward.In specific secondary reactions, hydrogen is formed from water, in orderto upgrade the hydrocarbons by hydrotreating.

In this way, by means of the geometry of the enlarged bore sections andthe skillful arrangement of a plurality of enlarged bore sections,physical partition within the caverns can be influenced.

In development of the invention, the combustion of the combustiblematerial is extinguished by the pumped introduction of an extinguishant,more particularly by means of an extinguishing gas, CO₂ for example.

Combustion within the oil sand deposit or else only within the enlargedbore sections can be fully or partly extinguished in this way, in orderto be able to control combustion rate and temperature, for example.

In development of the invention, provision is made for introducing afirst, substantially vertical bore section down into the oil sanddeposit, for introducing a second, substantially horizontal bore sectioninto the oil sand deposit, starting from the first, vertical boresection, for introducing at least one third, substantially horizontalbore section into the oil sand deposit, starting from the first,vertical bore section or starting from a fourth, vertical bore section,the third, horizontal bore section being arranged with a vertical and/orhorizontal offset from the second, horizontal bore section and runningsubstantially parallel thereto, for at least sectional filling of thesecond, horizontal bore section and of the third, horizontal boresection with an explosive material, and for detonation of this explosivematerial, to enlarge the second, horizontal and third, horizontal boresections, for ignition of combustible material in the second and/orthird, horizontal bore section(s), to convert the hydrocarbon compoundspresent in the oil sand deposit into a liquid and/or gaseous state, andfor collection of the liquid and/or gaseous hydrocarbon compounds.

In this way a particularly advantageous arrangement of the individualenlarged bore sections with respect to one another is achieved.

In development of the invention, two or more second, horizontal boresections and two or more third, horizontal bore sections are arranged inplanes which each run parallel to one another.

In this way, a matrix of enlarged bore sections can be formed within theoil sand deposit, this being extremely advantageous for controlledpropagation of a flame front in the oil sand deposit and also for thecreation of defined sinks or collecting basins for liquid and/or gaseoushydrocarbon compounds. The oil sand deposits can be exploited morecompletely and also more environmentally as a result, since, forexample, combustion processes can be extinguished completely by blownintroduction of CO₂.

In development of the invention, two or more second, horizontal boresections and two or more third, horizontal bore sections are arranged ina plane at a predetermined distance from one another.

In development of the invention, provision is made for introducing atleast one first, substantially vertical bore section down into the oilsand deposit, for introducing at least one fourth, substantiallyvertical bore section down into the oil sand deposit, substantiallyparallel to the first, vertical bore section, for at least sectionalfilling of the first and/or fourth vertical bore section(s) with anexplosive material, and for detonating this explosive material, toenlarge the first and/or fourth vertical bore section(s), for ignitingcombustible material in the first and/or fourth vertical boresection(s), to convert the hydrocarbon compounds present in the oil sanddeposit into a liquid and/or gaseous state, and for collecting theliquid and/or gaseous hydro-carbon compounds.

In this way, enlarged bore sections or caverns arranged vertically canbe provided. Then, as in the case of rectifying columns, gases, vapors,and liquids can be fed in and tapped off at different heights. In thisway as well it is possible to design an underground refinery.

In development of the invention, the first and fourth vertical boresections are connected by means of horizontal bore sections, with atleast one horizontal bore section connecting the vertical bore sectionsin an upper region, and at least one horizontal bore section connectingthe vertical bore sections in a lower region.

In this way it is possible to enable a targeted flow regime in theunderground caverns.

In development of the invention, at least one bore section is sealed offfrom the atmosphere. For example, connections between the undergroundcaverns and the atmosphere are sealed off provisionally, at leastpartly, by means of an expandable or inflatable plug. An expandable plugcasing is first expanded, for example, with air and/or with a fluid,resulting in an impervious seal in the borehole. Alternatively oradditionally to air, for example, water, bentonite slurry, or flowableconcrete can also be used for filling. This plug can thereafter bebackfilled, for example with sand, gravel, bentonite slurry and/orconcrete. In this way a cavern can be sealed off from the atmosphere orelse from other caverns, in order to create an underground system ofcaverns and connections that can be utilized as an underground refinery.

Further features and advantages of the invention will become apparentfrom the claims and from the following description of preferredembodiments of the invention, in connection with the drawings.Individual features of the different embodiments shown may be combinedarbitrarily with one another, without exceeding the scope of theinvention. In the drawings:

FIG. 1 shows a schematic representation of a first step in the method ofthe invention,

FIG. 2 shows a schematic representation of a further step in the methodof the invention,

FIG. 3 shows a schematic representation of a further step in the methodof the invention,

FIG. 4 shows a schematic representation of a further step in the methodof the invention,

FIG. 5 shows an arrangement of underground bore sections in accordancewith the method of the invention in a second embodiment,

FIG. 6 shows the arrangement of underground bore sections in accordancewith the method of the invention in a third embodiment,

FIG. 7 shows the arrangement of underground bore sections in accordancewith the method of the invention in a fourth embodiment,

FIG. 8 shows the arrangement of underground bore sections in accordancewith the method of the invention in a fifth embodiment,

FIG. 9 shows a schematic representation of a further step in the methodof the invention,

FIG. 10 shows an arrangement of underground bore sections in accordancewith the method of the invention in a sixth embodiment, and

FIG. 11 shows an arrangement of underground bore sections in accordancewith the method of the invention in a seventh embodiment.

The representation in FIG. 1 shows, schematically, a section through theuppermost region of the Earth's crust. Arranged beneath a surface 10 ofthe Earth is, first of all, an intermediate layer 12, followed then byan oil sand deposit 14. The oil sand deposit 14 is situated, forexample, at a depth of more than 75 m, corresponding to the thickness ofthe layer 12, and so the exploitation of the oil sand deposit 14 byopen-cast mining is no longer rational. The oil sand deposit 14 musttherefore be exploited using what is called an in situ method. Inaccordance with the invention, for this purpose, a drilling apparatus 16is first used to drill vertically through the layer 12, with a first,substantially vertical bore section 18, down into the oil sand deposit14, and then, subsequent to the substantially vertical section 18, asubstantially horizontal, second bore section 20 is disposed runningwithin the oil sand deposit 14. This second, substantially horizontalbore section 20 is then filled sectionally, over a length indicated bymeans of the double-ended arrow 22, with a gellike explosive.

This gellike explosive is then detonated—see FIG. 2. The undergroundexplosion within the oil sand deposit 14 causes the second, horizontalbore section 20 to be enlarged in a radial direction, thus producing anunderground cavern 24, as shown in FIG. 3. This underground cavern 24runs substantially horizontally. The walls of the underground cavern 24are composed of compacted oil sand, which as a consequence of theunderground explosion is displaced radially outward from the boresection 20 and, as a result, compacted. The cavern 24 is thereforestable and communicates with the drilling apparatus 16 via the boresection 18.

In accordance with FIG. 3, a second drilling apparatus 26 is used tointroduce a third, substantially vertical bore section 28 through thelayer 12 down into the oil sand deposit 14, which is then continued, asshown in FIG. 1, through a fourth, substantially horizontal boresection. As elucidated using FIGS. 1 to 3, this fourth, horizontal boresection is then likewise filled sectionally with gellike explosive andthen enlarged by the explosion of this gellike explosive. This producesa second underground cavern 30 running substantially horizontally withinthe oil sand deposit 14. The two underground caverns 24 and 30 arearranged substantially at the same height within the oil sand deposit14, and run approximately parallel to one another. The representation inFIG. 4 is schematic, but is intended to show perspective, and so the twounderground caverns 24 and 30 are arranged parallel to one another androughly at the same height or same depth within the oil sand deposit.

Arranged beneath the two caverns 24 and 30 is a pumping pipe 32, whichcommunicates with a pumping station 34 on the Earth's surface 10.

Into both the underground cavern 24 and the underground cavern 30,combustible material is next either introduced, or combustible materialis formed within the caverns 24 and 30 by the introduction of additives,as for example the blown introduction of air. The combustible materialthen present within the caverns 24 and 30, combustible gas for example,is then ignited by pyrotechnic means, for example, so that combustiondevelops and a flame front propagates, starting from the two caverns 24and 30. One such flame front is indicated in the case of the cavern withthe reference numeral 36. The pressure produced as a result of thecombustion within the caverns 24 and 30 ensures a flow of gas in thedirection of the arrows 38 and 40, in other words from the cavern 24toward the cavern 30, and in the opposite direction. The oil sanddeposit 14 consists of porous material, and so combustion and anassociated flow of gas can propagate within the oil sand deposit 14. Theprogress of the flame front 36 between the two caverns 24 and 30, with aflame front surrounding the cavern 24 not being shown, ensures heatingof the oil sand situated between the two caverns 24 and 30, and,consequently, ensures liquefaction of the bitumen situated between thetwo caverns 24 and 30. This liquefied bitumen can then be pumped off viathe bore 32; however, the liquefied bitumen will also collect within thecaverns 24 and 30 and can then easily be pumped off from these caverns.The same applies to gaseous hydrocarbon compounds, which will preferablycollect within the caverns 24 and 30.

Following depletion of the oil sand deposit 14 in the region between thecaverns 24 and 30, combustion can be extinguished by pumping CO₂ intothe caverns 24 and 30. This CO₂ will then spread, starting from thecaverns 24 and 30 and likewise in the direction of the arrows 38 and 40,toward the respective opposite cavern 30 or 24, and the combustion ofthe oil sand deposit will be completely extinguished as a result. Thispumped introduction of CO₂ may be used not only to extinguish thecombustion but also, at the same time, for the permanent storage of CO₂.

The representation in FIG. 5 shows an arrangement of underground caverns42, 44, and 46 in accordance with the method of the invention, in afurther embodiment. The caverns 42, 44, and 46 are arranged within theoil sand deposit 14 and, as described with reference to FIGS. 1 to 3,are formed by arranging first vertical, then horizontal bore sectionsand then by enlarging the horizontal bore sections by inserting anddetonating gellike explosive. Respective vertical bore sections aremerely indicated in FIG. 5 with the reference numerals 48. The verticalbore sections 48 may be permanently sealed with concrete, for example.The representation in FIG. 5 is merely the schematic representation ofthe arrangement of the underground caverns 42, 44, and 46, but not oftheir production by the sinking of suitable bores. The vertical boresections 48 should therefore be understood purely schematically andillustratively.

The underground caverns 42, 44, and 46 arranged horizontally, roughly atthe same height, and parallel to one another within the oil sand deposit14 are connected to one another by means of horizontal bores 50 and 52.The horizontal bore sections 50 and 52 are arranged roughly flush and/oroffset from one another and are continued in the form of substantiallyvertically running bore sections 54 and 56 and taken to pumping stations58 and 60 at the Earth's surface. Starting from the pumping station 58,a substantially vertical bore section 54 leads to the cavern 42, and isthen continued by means of the bore section 50 to the cavern 44.Starting from the cavern 44, a flow connection exists via the boresection 52 to the cavern 46, and from there the substantially verticalbore section 56 leads to the pumping station 60. The arrangement in FIG.5 shows the geometrical arrangement of the caverns 42, 44, and 46 afterthe enlargement of corresponding bore sections by means of explosive.

The arrangement shown schematically in FIG. 5 represents an undergroundrefinery. Accordingly, via the pumping station 58 and the bore section54, air and other substances are introduced into the cavern 42. In thecavern 42 there is a combustion zone, and here, water is supplied, aswell as air, in order, with pyrolysis coke, to form hydrogen and carbonmonoxide (synthesis gas) for the hydrotreating and for the cracking ofthe hydrocarbon compounds from the oil sand deposit 14. Upgrading of thebitumen, or cracking, takes place in the cavern 44. In the cavern 46,crude oil and light gas are deposited. Off-gas as well is collected inthe cavern 46, and then off-gas, crude oil, and gaseous hydrocarboncompounds as well can be pumped off via the pumping station 60. Withinthe cavern arrangement in FIG. 5 there is therefore a flow directionfrom the cavern 42 via the cavern 44 into the cavern 46. The cavern 42forms a heating zone, the cavern 44 a conversion zone, and the cavern 46a suction-withdrawal or pumping-off zone.

The representation in FIG. 6 shows an arrangement of underground boresections in accordance with the method of the invention, in a furtherembodiment. Three underground caverns 62, 64, and 66 are arranged herein parallel to one another within an oil sand deposit, but also atdifferent depth levels. The caverns 62, 64, and 66 are connected to oneanother by bore sections 68 and 70. In the cavern 62 there is a heatingzone, in which combustion takes place. In the middle cavern 64 there isa conversion zone, and in the uppermost cavern 66 there is asuction-withdrawal zone. The embodiment of FIG. 6 is intended for theexploitation of gaseous hydrocarbon compounds, and ensures quickcombustion and quick conversion, since the light, gaseous hydrocarboncompounds will rise rapidly along the bore sections 68 and 70 into theuppermost cavern 66, from which they can be pumped off. This predominantflow direction is indicated in FIG. 6 by the arrow 72.

FIG. 7 shows an arrangement of underground bore sections in accordancewith the method of the invention, in a further embodiment. Threeunderground caverns 74, 76, and 78 are arranged parallel to one anotherbut at different depths in the oil sand deposit, and are connected toone another by means of bore sections 80 and 82. In the uppermost cavern74 there is a combustion zone, in the middle cavern 76 there is aconversion zone, and in the lowermost cavern 78 there is a pumping-offzone. A predominant flow direction between the caverns 74, 76, and 78 isindicated by means of the arrow 84. The arrangement according to FIG. 7ensures slow propagation of the combustion gases, starting from theheating zone in the cavern 74. Liquid hydrocarbon compounds willpreferably collect in the lowermost cavern 78, which they reach as aresult of gravity. On account of the slow process, in which the hotcombustion gases spend a long time in the respective regions of the oilsand deposit, good and thorough separation of light and heavy crude oilcan take place.

The representation in FIG. 8 shows an arrangement of underground boresections in accordance with the method of the invention, in a furtherembodiment. Three underground caverns 86, 88, and 90 are arrangedparallel to one another and at different depths within an oil sanddeposit. The cavern 86 on the left in FIG. 8 is arranged the lowest, thecavern in the middle in FIG. 8 the highest, and the cavern on the rightin FIG. 8 at a depth which lies roughly between the depths of thecaverns 86 and 88. The caverns 86 and 88 are connected by a bore section92, which runs upward at a slope, and the caverns 88 and 90 areconnected by a bore section 94, which runs downward at a slope.

In the deepest cavern 86, on the left in FIG. 8, there is a combustionzone, which then propagates, as indicated with the reference numeral 96,within the oil sand deposit toward the middle cavern 88. As a result, inaccordance with the arrow 98, combustion gases rise preferably towardthe middle cavern 88. The middle cavern 88 represents a conversion zoneand, since the pumping-off zone, in the form of the cavern 90 on theright in FIG. 8, is situated lower than the middle cavern 88, a higherresidence time is achieved in the conversion zone, corresponding to thecavern 88.

The representation in FIG. 9 shows the arrangement of the caverns 86,88, and 90 from FIG. 8, with the sealing of a connection between thecavern 88 and the atmosphere being shown, by way of example, above theEarth's surface 10. A connection 101 between the drilling apparatus 100and the cavern 88 is then to be sealed, the connection 101 having servedoriginally for the drilling of connection 92. For this purpose, aninflatable, elastic plug 102 is first introduced into the bore,adjoining the cavern 88, and is expanded using air, water, bentoniteslurry, or flowable concrete, for example, until the bore section isfully filled and thus sealed off. This expandable plug 102 is thenbackfilled between the drilling apparatus 100 and the plug 102, withsand, gravel, bentonite slurry, concrete or the like, for example. Aconnection between the cavern 88 and the atmosphere can be fully closedin this way. This can be done in order to produce defined flowconditions between the caverns 86, 88, and 90 during operation. This mayalso take place after the end of the exploitation of the oil sanddeposit. For example, after the end of exploitation, CO₂ is passed intothe caverns 86, 88, and 90 in order to halt the combustion and to acertain extent to deposit CO₂. After introduction of the plug 102 andthe backfilling 104, the caverns 86, 88, and 90 are then separated fromthe atmosphere, and so the deposited CO₂ is no longer able to escape.

The representation in FIG. 10 shows a further arrangement of undergroundbore sections in accordance with the method of the invention, in afurther embodiment. Arranged beneath the Earth's surface 10 and withinan oil sand deposit 14 there is a matrix of bore sections, whichexhibits a total of four planes 106, 108, 110, and 112 at in each caseeight caverns arranged parallel to one another and at the same height.The number of four planes and also the number of in each case eightcaverns arranged parallel to one another and at the same height ismerely exemplary. The caverns in each plane 106, 108, 110, and 112 areeach connected to one another by means of a horizontal bore 114, 116,118, and 120.

The arrangement of underground bore sections and caverns shown in FIG.10 forms an underground refinery, by means of which it is possible notonly to exploit the oil sand deposit 14 but also, at the same time, toconvert the hydrocarbon compounds still within the oil sand deposit 14.

The representation in FIG. 11 shows an arrangement of underground boresections in accordance with the invention, in a further embodiment.

According to FIG. 11, three vertical bores 122, 124, and 126 have beenintroduced in parallel to one another in the Earth's surface 10 downinto the oil sand deposit 14. Bore sections situated within the oil sanddeposit 14 have been enlarged by explosion, thus forming threevertically arranged underground caverns 128, 130, and 132. In the regionof their top end, the underground caverns 128, 130, and 132 areconnected to one another by means of horizontally running bores 134 and136, and in the region of their lower end by means of horizontal bores138 and 140. The caverns 128 and 130 communicate via the bores 134 and138, and the caverns 130 and 132 communicate with one another via thebores 136 and 140. An arrow 142 symbolizes the introduction of air orother substances into the cavern 128 on the left in FIG. 11. This isdone via one or more bores, which for clarity are not shown in FIG. 11.The pumping-off of liquid hydrocarbon compounds from the cavern 132 onthe right in FIG. 11 is indicated by means of an arrow 144. Liquidhydrocarbon compounds collect in the cavern 132, in accordance withgravity, at its bottom end, and so liquid hydrocarbon compounds are alsopumped off from there. The pumping-off of gaseous hydrocarbon compoundsfrom the cavern 132 is indicated by means of an arrow 146. Gaseoushydrocarbon compounds collect in the cavern 132 preferably in the regionof its upper end, and so gaseous compounds are also pumped off fromthere.

The arrangement of the underground caverns 128, 130, and 132 that isshown in FIG. 11 also forms an underground refinery with a heating zonein the region of the left-hand cavern 128, a conversion zone in theregion of the middle cavern 130, and a pumping-off zone in the region ofthe right-hand cavern 132.

1. A method for extracting hydrocarbon compounds, especially crude oil,from underground oil sand deposits, with the steps of introducing atleast two bore sections parallel to one another into the oil sanddeposit, at least sectionally filling the bore sections with anexplosive material, detonating the explosive material to enlarge thebore sections, igniting combustible material in at least one of the boresections, to convert the hydrocarbon compounds present in the oil sanddeposit into a liquid and/or gaseous state, and collecting thehydrocarbon compounds present in a liquid and/or gaseous state.
 2. Themethod as claimed in claim 1, including compacting of the oil sandmaterial surrounding the outer surface of the bore sections, by means ofthe enlarging of the bore sections after detonating of the explosivematerial.
 3. The method as claimed in claim 1, wherein the explosivematerial is a gellike explosive.
 4. The method as claimed in claim 1,wherein air is supplied to the bore sections to promote the combustionof the combustible material, and in that off-gases formed duringcombustion are drawn off under suction.
 5. The method as claimed inclaim 1, wherein water, steam, oxygen, more particularly atmosphericoxygen, carbon monoxide and/or carbon dioxide is supplied to ortargetedly withdrawn from the bore sections in order to influencetemperature and physical conversions, such as cracking and upgrading,for example, in the region of the bore sections.
 6. The method asclaimed in claim 1, wherein the hydrocarbon compounds present in the oilsand deposit are split by means of the combustion into hydrocarbonchains of different lengths and different aggregate states, withshort-chain, lighter and/or gaseous chain components rising upward, andlong-chain, heavier and/or liquid chain components falling downward. 7.The method as claimed in claim 1, wherein the combustion of thecombustible material is extinguished by the pumped introduction of anextinguishant, more particularly by means of an extinguishing gas, CO₂for example.
 8. The method as claimed in claim 1, including sealing offat least one bore section from the atmosphere.
 9. The method as claimedin claim 1, with the steps of introducing a first, substantiallyvertical bore section down into the oil sand deposit, introducing asecond, substantially horizontal bore section into the oil sand deposit,starting from the first, vertical bore section, introducing at least onethird, substantially horizontal bore section into the oil sand deposit,starting from the first, vertical bore section or starting from afourth, vertical bore section, the third, horizontal bore section beingarranged with a vertical and/or horizontal offset from the second,horizontal bore section and running substantially parallel thereto, atleast sectionally filling the second, horizontal bore section and thethird, horizontal bore section with an explosive material, anddetonating this explosive material to enlarge the second, horizontal andthird, horizontal bore sections, igniting combustible material in thesecond and/or third, horizontal bore section(s), to convert thehydrocarbon compounds present in the oil sand deposit into a liquidand/or gaseous state, and collecting the liquid and/or gaseoushydrocarbon compounds.
 10. The method as claimed in claim 9, wherein twoor more second, horizontal bore sections and two or more third,horizontal bore sections are arranged in planes which each run parallelto one another.
 11. The method as claimed in claim 1, wherein two ormore second, horizontal bore sections and two or more third, horizontalbore sections are arranged in a plane at a predetermined distance fromone another.
 12. The method as claimed in claim 1, with the steps ofintroducing at least one first, substantially vertical bore section downinto the oil sand deposit, introducing at least one fourth,substantially vertical bore section down into the oil sand deposit,substantially parallel to the first, vertical bore section,characterized by at least sectionally filling the first and/or fourthvertical bore section(s) with an explosive material, and detonating thisexplosive material to enlarge the first and/or fourth vertical boresection(s), igniting combustible material in the first and/or fourthvertical bore section(s), to convert the hydrocarbon compounds presentin the oil sand deposit into a liquid and/or gaseous state, andcollecting the liquid and/or gaseous hydrocarbon compounds.
 13. Themethod as claimed in claim 12, including connecting the first and fourthvertical bore sections by means of horizontal bore sections, with atleast one horizontal bore section connecting the vertical bore sectionsin an upper region, and at least one horizontal bore section connectingthe vertical bore sections in a lower region.